US8029073B2 - Motor vehicle rapid braking brake booster - Google Patents

Motor vehicle rapid braking brake booster Download PDF

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Publication number
US8029073B2
US8029073B2 US12/265,845 US26584508A US8029073B2 US 8029073 B2 US8029073 B2 US 8029073B2 US 26584508 A US26584508 A US 26584508A US 8029073 B2 US8029073 B2 US 8029073B2
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US
United States
Prior art keywords
piston
sleeve
master cylinder
brake booster
travel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US12/265,845
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English (en)
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US20090115245A1 (en
Inventor
Jean-Marc Attard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Assigned to ROBERT BOSCH GMBH reassignment ROBERT BOSCH GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ATTARD, JEAN-MARC
Publication of US20090115245A1 publication Critical patent/US20090115245A1/en
Application granted granted Critical
Publication of US8029073B2 publication Critical patent/US8029073B2/en
Expired - Fee Related legal-status Critical Current
Adjusted expiration legal-status Critical

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/24—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being gaseous
    • B60T13/46—Vacuum systems
    • B60T13/52—Vacuum systems indirect, i.e. vacuum booster units
    • B60T13/573—Vacuum systems indirect, i.e. vacuum booster units characterised by reaction devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
    • B60T13/24—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being gaseous
    • B60T13/46—Vacuum systems
    • B60T13/52—Vacuum systems indirect, i.e. vacuum booster units
    • B60T13/565—Vacuum systems indirect, i.e. vacuum booster units characterised by being associated with master cylinders, e.g. integrally formed

Definitions

  • the invention relates to a brake booster and more specifically to a rapid actuation brake booster that can be applied in particular to motor vehicles.
  • This system comprises, as depicted in FIGS. 1 and 2 :
  • a casing 2 of longitudinal axis X, containing a skirt 6 mounted such that it can slide axially in a sealed manner in the casing and which delimits a low-pressure first chamber 8 known as the front chamber and a variable-pressure second chamber 10 known as the rear chamber,
  • valve shutter 46 In the rest position ( FIGS. 1 and 2 ), the valve shutter 46 is lifted off the first valve seat or equalizing seat 48 (borne by the sleeve 54 ) and places the front chamber 8 in communication with the rear chamber 10 . The valve shutter 46 presses against the intake valve second seat 50 thus isolating the rear chamber from atmospheric pressure.
  • the control rod 28 is moved axially forward, the valve shutter 46 then comes to press against the first valve seat 48 , isolating the rear chamber from the front chamber, and lifts off the second seat 50 and allows air at atmospheric pressure to be supplied to the rear chamber. Because of the pressure difference between the front chamber and the rear chamber, the skirt 6 and the piston 12 are made to move forward.
  • the first valve seat 48 borne by the sleeve 54 is immobile while the clearance C between the key 84 and the front end of the second slots 88 is not closed up.
  • the spring 58 keeps the sleeve 54 in a determined axial position relative to the casing of the booster as long as the piston 12 has not covered a determined travel C ( FIG. 2 ).
  • the hydraulic piston of the master cylinder is pushed by the pneumatic piston, which itself carries along the auxiliary piston 126 which moves away from the sensor feeler. Once the pressure in the master cylinder is high enough for the auxiliary piston 126 to be able to overcome the jump spring 128 , the auxiliary piston is pushed back toward the sensor feeler until it comes into contact therewith and then passes the reaction on from the hydraulic circuit to the brake pedal.
  • the travel C is preferably chosen such that it corresponds to the dead travel of the master cylinder, that is to say to the travel that the hydraulic piston has to cover within the master cylinder in order to begin to cause the pressure of the brake fluid to rise in the brakes.
  • the driver feels through the pedal only the travel needed to close the equalizing valve and open the intake valve and does not perceive the dead travel of the master cylinder.
  • Driver comfort is thus improved, because the driver has the impression of immediate braking.
  • One subject of the invention is therefore a brake booster comprising:
  • a three-way valve actuated by a control rod mounted in a longitudinal passage pierced in the pneumatic piston, said control rod being connected via a first longitudinal end to a brake pedal,
  • a slide valve plunger able to move, in said piston, along said longitudinal axis under the control of a second end of said control rod, said slide valve plunger allowing the force of the control rod to be applied to a hydraulic piston of a master cylinder, said skirt-piston assembly transmitting a pneumatic boost force to the hydraulic piston of the master cylinder,
  • a sleeve mounted such that it can slide in a sealed manner in the pneumatic piston along said longitudinal axis over a determined travel.
  • the three-way valve comprises a first and a second valve seat, and a valve shutter intended to be pressed against the first and/or the second valve seat.
  • the first valve seat is borne by a first longitudinal end of the sleeve.
  • the second valve seat is borne by a first longitudinal end of the slide valve plunger.
  • the booster also comprises:
  • a device for transmitting the pressure of the master cylinder to the sleeve which tends to apply a rearward force to the sleeve a device for transmitting the pressure of the master cylinder to the sleeve which tends to apply a rearward force to the sleeve.
  • the elastic device to comprise a first spring.
  • the device for transmitting the pressure of the master cylinder comprises an auxiliary piston coaxial with the primary piston of the master cylinder.
  • This auxiliary piston is intended to apply a force to the sleeve via the device that transmits the pressure of the master cylinder.
  • this transmission device comprises a second spring.
  • the pneumatic piston may then comprise an end-stop shoulder and the sleeve may comprise a travel-limiting component intended to butt against said end-stop shoulder in order to limit the travel of the sleeve inside the piston of the booster.
  • bearing piece which bears against the casing of the booster and which has a first part that penetrates an opening in the pneumatic piston and against which this piston is intended to bear, and a second part which enters an opening in the sleeve and which is intended to limit the forward movement of the sleeve when the booster is at rest.
  • the load of the first spring is lower than the load of the second spring.
  • FIG. 1 a brake booster of the type known in the prior art and already described previously,
  • FIG. 2 a more detailed view of the brake booster of FIG. 1 , also described previously,
  • FIG. 3 one exemplary embodiment of the device according to the invention as applied to a pneumatic brake booster
  • FIG. 4 an enlarged view of the device according to the invention in FIG. 3 ,
  • FIG. 5 an alternative form of embodiment of the device of FIG. 4 .
  • FIGS. 3 and 4 One exemplary embodiment of the device of the invention will therefore be described with reference to FIGS. 3 and 4 .
  • FIG. 3 This device applies to a brake booster like that of FIG. 1 .
  • FIG. 3 only that part of the booster to which the device of the invention relates has been depicted.
  • the components depicted in FIGS. 3 and 4 bear the same references as those components of FIGS. 1 and 2 that perform the same functions.
  • FIG. 3 therefore partially depicts the casing of the booster in which a skirt 6 delimits a (low pressure) front chamber 8 and a rear chamber 10 that can be placed either at the same pressure as the front chamber or at atmospheric pressure.
  • a pneumatic piston 12 is secured to the skirt and slides along the axis X of the booster.
  • a sleeve 54 slides axially inside the piston 12 .
  • a slide valve plunger 32 slides axially inside the sleeve under the control of a control rod 28 controlled by a brake pedal, not depicted.
  • a three-way valve situated inside the piston 12 could be used either to place the first chamber 8 and the rear chamber 10 in communication, or to place the rear chamber at atmospheric pressure, or to isolate the rear chamber.
  • the three-way valve comprises a valve shutter 46 of annular shape capable of being in contact either with an equalizing valve seat 48 borne by an annular end of the sleeve 54 or with an intake valve seat 50 borne by an annular end of the slide valve plunger 32 .
  • the sleeve 54 is normally pushed forward (to the left in FIGS. 3 and 4 ) by a spring 70 .
  • the spring 70 bears, at one end, against the rear face of a shoulder 71 situated at the front of the sleeve 54 and, at another end, against the front face 72 of a shoulder of the piston 12 .
  • the spring 70 therefore tends to push the sleeve 54 forward (to the left in the figures) so that the valve seat 48 tends to move away from the valve shutter 46 .
  • auxiliary piston 126 is capable of exerting a rearward force on the sleeve 54 .
  • This force is applied via an elastic device comprising, for example, a spring 128 a contained between the pistons 122 and 126 .
  • a stop piece 90 presses against the internal wall of the casing of the booster. It allows the piston to prevent the sleeve from moving forward.
  • the spring 133 pushes the pneumatic piston 12 back to the rear (to the right in FIGS. 3 and 4 ).
  • the face 13 of the opening 14 in the piston presses backward against the piece 90 and presses this piece 90 against the casing.
  • Part of the piece 90 lies in an opening 55 in the sleeve 54 .
  • the piece 90 therefore presses backward against the edge 56 of the opening 55 in the sleeve. This sleeve cannot therefore move forward (to the left in FIGS. 3 and 4 ).
  • the sleeve 54 is pushed forward by the spring 70 and presses the sleeve 54 against the bearing piece 90 .
  • valve seat 50 pushes the valve shutter 46 backward, this valve shutter being lifted off the equalizing valve seat 48 borne by the sleeve 54 .
  • This space between the valve shutter 46 and the valve seat 48 places the front chamber 8 in communication with the rear chamber 10 .
  • the valve shutter 46 bears against the intake valve seat 50 and thus isolates the rear chamber 10 from atmospheric pressure.
  • the control rod 28 is moved axially forward (to the left in the figures) and the slide valve plunger 32 moves forward.
  • the valve seat 50 moves forward.
  • the valve shutter 46 also moves forward and is pressed against the equalizing valve seat 48 borne by the sleeve 54 .
  • the rear chamber 10 is isolated from the front chamber 8 .
  • the intake valve seat 50 lifts away from the valve shutter 46 , allowing air at atmospheric pressure to be supplied to the rear chamber 10 .
  • the piston 12 pushes the piston 122 of the master cylinder 120 forward.
  • the pressure in the master cylinder increases.
  • the pressure in the master cylinder tends to push the auxiliary piston 126 back.
  • the piston 126 presses backward against the face 74 of the sleeve 54 via the washer 127 , the spring 128 and the washer 129 .
  • valve seat 48 moves closer to the valve shutter 46 .
  • valve shutter 46 comes into contact with the intake valve seat 50 and interrupts the supply of air at atmospheric pressure to the rear chamber. The driver then has to depress the brake pedal further in order to increase the intensity of braking.
  • valve shutter 46 is then in contact with the equalizing valve seat 48 of the sleeve 54 and with the intake valve seat 50 , thus interrupting the supply of air at atmospheric pressure to the rear chamber.
  • the travel C (see FIG. 4 ) represented by the distance covered by the face 71 of the sleeve will preferably be chosen such that it corresponds to the dead travel of the master cylinder, that is to say to the travel that the hydraulic piston needs to cover within the master cylinder in order to achieve the onset of the increase in brake fluid pressure in the brakes.
  • the slide valve plunger 32 is carried backward with the control rod.
  • the intake valve seat 50 comes into contact with the valve shutter 46 and carries the valve shutter 46 away from the equalizing seat 48 , thus placing the front chamber 8 in communication with the rear chamber 10 .
  • the pressures across the skirt 6 can then equalize, so the skirt 6 returns to the rest position.
  • the load of the spring 128 is preferably higher than that of the spring 70 .
  • a travel limiting piece 75 may be provided, this bearing the bearing face 71 for the spring 70 .
  • the position of this piece 75 is axially adjustable on the sleeve 54 .

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Braking Systems And Boosters (AREA)
  • Braking Arrangements (AREA)
US12/265,845 2007-11-06 2008-11-06 Motor vehicle rapid braking brake booster Expired - Fee Related US8029073B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0707810 2007-11-06
FR0707810A FR2923200B1 (fr) 2007-11-06 2007-11-06 Servomoteur d'assistance au freinage rapide pour vehicule automobile.

Publications (2)

Publication Number Publication Date
US20090115245A1 US20090115245A1 (en) 2009-05-07
US8029073B2 true US8029073B2 (en) 2011-10-04

Family

ID=39538019

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/265,845 Expired - Fee Related US8029073B2 (en) 2007-11-06 2008-11-06 Motor vehicle rapid braking brake booster

Country Status (5)

Country Link
US (1) US8029073B2 (de)
EP (1) EP2058194B1 (de)
AT (1) ATE477973T1 (de)
DE (1) DE602008002202D1 (de)
FR (1) FR2923200B1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120227579A1 (en) * 2009-10-29 2012-09-13 Lucas Automotive Gmbh Vacuum Brake Servo for a Motor Vehicle Braking System
US12523278B2 (en) * 2021-08-20 2026-01-13 Zf Active Safety Gmbh Actuating unit, brake booster, vehicle brake system and subassembly therefor

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102537351B (zh) * 2011-12-31 2014-09-10 重庆长安汽车股份有限公司 一种塑料离合主缸密封垫
US9657751B2 (en) 2012-12-08 2017-05-23 Ford Global Technologies, Llc Pneumatic pressure brake booster system
FR3030740B1 (fr) * 2014-12-18 2016-12-30 Coutier Moulage Gen Ind Dispositif de mesure de pression et systeme de freinage comprenant un tel dispositif de mesure de pression

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2782044A1 (fr) 1998-08-07 2000-02-11 Continental Teves Ag & Co Ohg Servofrein equipe d'une fonction de freinage d'urgence
US6564692B2 (en) * 2000-12-13 2003-05-20 Bosch Braking Systems Co., Ltd. Brake booster
US7089846B2 (en) * 2003-06-03 2006-08-15 Advics Co., Ltd. Negative pressure type booster device
US7201456B2 (en) 2002-09-19 2007-04-10 Robert Bosch Gmbh Pneumatic brake booster
US7267040B2 (en) 2003-06-23 2007-09-11 Robert Bosch Gmbh Booster with reduced dead travel and a braking system comprising such a booster
US7685926B2 (en) * 2003-05-16 2010-03-30 Bosch Corporation Negative pressure booster

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2782044A1 (fr) 1998-08-07 2000-02-11 Continental Teves Ag & Co Ohg Servofrein equipe d'une fonction de freinage d'urgence
US6564692B2 (en) * 2000-12-13 2003-05-20 Bosch Braking Systems Co., Ltd. Brake booster
US7201456B2 (en) 2002-09-19 2007-04-10 Robert Bosch Gmbh Pneumatic brake booster
US7685926B2 (en) * 2003-05-16 2010-03-30 Bosch Corporation Negative pressure booster
US7089846B2 (en) * 2003-06-03 2006-08-15 Advics Co., Ltd. Negative pressure type booster device
US7267040B2 (en) 2003-06-23 2007-09-11 Robert Bosch Gmbh Booster with reduced dead travel and a braking system comprising such a booster

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
FR 0707810 Search Report and Written Opinion.

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120227579A1 (en) * 2009-10-29 2012-09-13 Lucas Automotive Gmbh Vacuum Brake Servo for a Motor Vehicle Braking System
US9260097B2 (en) * 2009-10-29 2016-02-16 Lucas Automotive Gmbh Vacuum brake servo for a motor vehicle braking system
US12523278B2 (en) * 2021-08-20 2026-01-13 Zf Active Safety Gmbh Actuating unit, brake booster, vehicle brake system and subassembly therefor

Also Published As

Publication number Publication date
DE602008002202D1 (de) 2010-09-30
ATE477973T1 (de) 2010-09-15
EP2058194A1 (de) 2009-05-13
US20090115245A1 (en) 2009-05-07
FR2923200B1 (fr) 2009-11-20
FR2923200A1 (fr) 2009-05-08
EP2058194B1 (de) 2010-08-18

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Owner name: ROBERT BOSCH GMBH, GERMANY

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Effective date: 20191004